1. Field of Technology
The present invention generally relates to an information recording and/or reproducing apparatus operable with the use of a cassette containing an information recording medium and, more particularly, to a cassette holder structure employed in such apparatus.
For the purpose of the present invention, the apparatus of the type referred to above includes a video tape recorder (VTR), a digital audio tape recorder (DAT) and the like, and, depending on the type of the apparatus, the information recording medium may be a length of magnetic recording tape, a magnetic disk, an optical disk or the like.
2. Description of the Prior Art
In describing an example of the prior art considered pertinent to the present invention, reference will be made to a video tape recorder and a cassette holder structure used therein, the prior art cassette holder structure being schematically shown in FIGS. 1 and 2 of the accompanying drawings.
Referring first to FIG. 1, a generally rectangular, standardized cassette 1 is shown as held in position ready to be loaded in a holder structure generally identified by H. The holder structure H comprises a cassette holder 2 having a cassette receiving mouth defined therein for receiving the cassette 1 and supported for movement between a cassette receiving position, as shown therein, and a loaded position, a plurality of, for example, two retaining leaf springs 3 secured to a ceiling portion of the cassette holder 2 to confront the cassette receiving mouth so that, when the cassette 1 is inserted into the cassette receiving mouth in a direction shown by the arrow A, the cassette 1 so inserted can be retained in position within the cassette holder 2, and a support structure 4 including a pair of side walls 4b and a top wall 4c assembled together so as to represent a shape generally similar to the shape of an inverted figure "U", each of the side walls 4b having a respective guide slot 4a defined therein in alignment with each other.
The cassette holder 2 has a pair of pins 2a protruding outwardly therefrom in a direction away from each other and axially aligned with each other, the cassette holder 2 being movably supported with the pins 2a engaged in the respective guide slots 4a.
The prior art holder structure H is so designed and so structured that, when the cassette 1 is inserted into the cassette receiving mouth of the holder 2 and a continued external pushing force is applied to the holder 2 through the cassette 1, the holder 2 can be moved from the cassette receiving position towards the loaded position with the pins 2a guided along the guide slots 4a and can be subsequently drawn by a motor-driven cassette loader (not shown) towards the loaded position. As best shown in FIG. 2, when the cassette 1 is completely inserted into the cassette receiving mouth of the cassette holder 2, not only is a front edge of the cassette 1 brought into engagement with a stopper 2d integral with the cassette holder 2, but also the cassette 1 itself is substantially immovably held in position by the retaining springs 3.
However, it has been found that the prior art holder structure H of the above described construction poses the following problem. Since only the retaining springs 3 are an effective means for retaining the cassette 1, once inserted into the cassette holder 2, in position inside the cassette holder 2, and when during the loading of the cassette 1, that is, during the movement of the cassette holder 2 from the cassette receiving position towards the loaded position, the cassette 1 is loaded by reason of its contact with a component of the holder structure or by reason of shock and/or vibrations imposed thereon, the cassette 1 tends to deviate from the right position inside the holder 2 to such an extent that, when at the loaded position, it will not be correctly set in position relative to, for example, a cylinder drum supporting magnetic recording and/or reproducing heads. Once this happens, not only can the information recording medium, such as the magnetic tape, be damaged, but also the apparatus may fail to operate properly.
The above described problem may be somewhat alleviated if the biasing force of each of the retaining springs 3 is increased enough to firmly hold the cassette 1 inserted into the holder 2. However, the use of springs 3 of this type poses a problem in that a correspondingly increased resistance may act on the insertion of the cassette 1 into the cassette holder 2, causing an operator to feel uncomfortable when inserting the cassette 1 into the cassette holder 2 and also causing the casset 1 itself to be readily damaged.